Gaelic Memories Photography September 2019
Aurora Borealis in Ireland
Capturing the majesty of Aurora Borealis is a very exciting experience for a photographer, pro or amateur. It’s also a very challenging experience; testing the photographer’s patience as well as their camera equipment.
When people think about seeing/capturing the Aurora, they generally think of Iceland, Finland and Norway. It’s surprising to some that we are able to capture this magnificent light display right here in Ireland.
Stephen Baxter Nikon D810 14mm 25sec f/2.8 ISO 800 7th October @21:34
What is the Aurora Borealis?
The Aurora is caused by the collision between electrically charged particles released from the sun that enter the earth’s atmosphere and collide with gases such as oxygen and nitrogen. The lights are seen around the magnetic poles of the northern and southern hemispheres.
In our hemisphere the phenomenon is referred to ‘The Northern Lights’ and many colours can be displayed including shades of red, green, yellow, violet and blue. The Aurora may show as towering curtains, light arcs, rippling curtains or light towers.
the Aurora can be very difficult, but luckily there are sites dedicated to the monitoring and prediction of solar activity, geomagnetic activity and real-time solar wind conditions, culminating in a reading called kp.
The Kp-index as a global Aurora indicator1
The kp number system is just a scale of geomagnetic activity. The kp numbers start at 0 and as the geomagnetic (aurora) strength increases, so too does the kp number. So kp 0 being a very weak or none existent aurora, right through to 9 being a major geomagnetic storm with auroras likely in France and even Northern Spain.
I use this website http://www.aurora-service.eu Scandinavia, run by enthusiastic volunteers. They provide free of charge a constantly updated 3hr predictions of the Aurora. This site has a number of tools and displays that monitor the elements needed for a successful Aurora prediction.
1. BZ Gauge – The Direction of the Interplanetary Magnetic Field
The BZ’s the most important factor for the prediction of capturing the Aurora; this gauge gives the direction of the interplanetary magnetic field, we need this gauge to read in the negative (Southward). This causes charged particles into the Van Allen belt2 around the earth. The resulting particles enter the Earths atmosphere colliding with gases (Oxygen & Nitrogen) this collision releases energy that emits light (Aurora Borealis).
2. Solar Wind Gauge
The solar wind is a stream of plasma (charged Particles) released from the Sun; the stream of particles varies in density, temperature, and speed over time and over solar longitude. These particles can escape the Sun’s gravity because of their high energy, from the high temperature of the corona and magnetic, electrical and electromagnetic phenomena in it.
3. Density Gauge
This gauge displays the current density of the solar winds, the higher the density the more likely we are to see the Aurora display. Ideally, for the optimal chance of capturing the Aurora, the BZ dial needs to read in the negative, and the Solar Wind gauge the higher the speed the better. For the Density gauge, higher is also better.
A camera, full-frame or crop sensor, a fast wide-angle lens, 24mm and below with an aperture f/2.8 to f/4.Remote or cable release (not essential but save having to depress the shutter manually reduces the likelihood on unintentional movement) sturdy tripod, flashlight, and extra batteries (the cold may reduce the battery longevity)
Stephen Baxter Nikon D810 14mm 10sec f/2.8 ISO 1600 20th December @17:28
Photographing at night can be difficult due to the low light situation, however, the same rules of exposure apply as to daytime photography. We need to allow sufficient light to be absorbed by the sensor to produce a useable image. It’s inevitable that the ISO (sensitivity) will need to be increased significantly; the shutter speed settings should ideally be less than 30 seconds, as longer shutter speeds will result in the stars trailing due to the rotation of the Earth.
Stephen Baxter Nikon D850 50mm 25sec f/2.8 ISO 1600 Lough Gara Sligo Sept 27th @ 23:04
- Focus the camera onto a lighted area approximately 12 feet (3.6 m) away 3(Hyperfocal distance for your lens may differ), once the focus is locked, turn off the autofocus on the camera body and the lens, also turn off any lens stabilisation such as VR or VC.
- Mount the camera on the tripod and ensure the tripod is on solid ground, level the camera, taking care not to alter the focus, frame the horizon to the north.
- Set the camera to manual and input the ISO, Shutter Speed, Aperture and set the white balance between 4000-5700K (Auto WB can be used)
- Now attach the remote shutter wired or wireless.
- Switch the camera to live view mode.
- Take a test shot to check framing, exposure and sharpness.
- Ensure you check the lens regularly; moisture can settle on the lens and ruin focus.
- Check the Histogram to ensure that the exposure is exposing slightly to the left (darker but not clipped), overexposure will result in lost detail and be unrecoverable. Exposing to the left may result in a darker image but this is easily recovered in post-editing. It may increase the noise slightly but you will have a very useable photograph.
- Regularly check (if you have a signal) the forecast on http://www.aurora-service.eu
- 10. And wait, the Aurora can take many hours to fully develop, keep looking to the North, you may see hints of red and a white hazy mist. You may also see light columns so bright and distinctive, the air feels electric and hopefully builds it a full-blown Aurora.
* The Aurora brightness is not a constant, it will fluctuate during its display and the camera settings may need to be altered to address the changes in luminosity.
Plan, plan and plan again, if possible do a check of the area during daylight hours, find a location that faces north and gives a clear view of the horizon away from major towns. Areas with water will add an extra dimension to your Aurora photograph. Check your phone works in the location and for any hazards that may be difficult to see at night.
Using the phases of the moon is critical when photographing the aurora borealis. A bright moon will spoil the Aurora display; try to coincide your aurora shoot before the moon rises above the horizon line or when in a new moon or old moon phase.
Unfortunately, we now live in an illuminated world and light pollution at night can dramatically interfere with night photography. Avoid facing towards a populated area to the north.
Don’t forget about the weather; check the local weather forecast to see if the skies are going to be clear, the heavy cloud will prevent the sight of the Aurora. Don’t forget to wear warm clothes, remember nights can be exceptionally cold. A flask with hot tea or coffee is a welcome relief in the early hours.
Dark locations are generally off the beaten track try to get a friend to accompany you. Carry a mobile phone and check you have a full battery and signal in the shoot location. If there is no signal arrange a time to check back in with home (if alone). Carry a bright flashlight with extra batteries to navigate or signal location. Wear suitable footwear with strong ankle support. Don’t forget your prescribed medications in case of a prolonged shoot or if you get into difficulty, also a first aid kit. Always carry some high-calorie snacks and water. Be discrete with the camera equipment, these are high-value items and can be a target for thieves. Park your car out of sight or in a brightly lit area.
Stephen Baxter Nikon D850 50mm 20sec f/2.8 ISO 2000 Lough Gara Sligo Sept 27th @ 00:43
Author Stephen Baxter (Gaelic Memories Photography)
Recommended Camera Store Whelan Cameras
1 http://www.aurora-service.eu Graphics by Aurora Service EU
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